Find The Time was born from my own need to schedule events. The training times of my frisbee group were not fixed, so every week we had to discuss back and fro to find the right time.

This plugin adds a mini-calendar to either the portal or the index-page (make sure to enter {$findthetime} at the appropriate spot in said template to actually see the calendar!).

Either you let your whole userbase use the same calendar, or you let Find The Time base its calendar on a user field (this could be the user's location, the user's preferred sport or maybe a new user field with the user's preferred calendar). In that case, every user only sees the events for, say, "football" or "volleyball", or maybe "Chicago" or "Austin".